April 3 is a special day in the world of telecommunications, as this is the day the first known mobile phone conversation took place.

On Wednesday, the 40th anniversary of the event, Martin Cooper, the engineer who made the first call on 3 April, 1973, was honoured with the 2013 Marconi Prize, recognising his contributions to the world of telecommunications.

"Motorola was one of the luckiest things that ever happened to me," Mr. Cooper told The Marconi Society. "If you wanted to change society it was the place to be. In 1965 I was given a new assignment to head the Portable Products Group. We had one over-riding belief: that people are inherently mobile."

At the time, AT&T, which invented the concept of cellular technology, was investing heavily in their own vision of the future of mobile communications and it seemed likely AT&T would be granted a monopoly by the FCC on the required spectrum.

All that changed on April 3, 1973, when, standing on a street corner in New York City, Martin Cooper demonstrated Motorola's handset prototype to a reporter by making the first public phone call on the handheld cellular phone. "I'm ringing you just to see if my call sounds good at your end," Cooper is reported to have said.

The original handset, named the DynaTAC (DYNamic Adaptive Total Area Coverage), was gigantic by modern standards, weighed over a kilo, and was 10-inches long. Since then, mobile phones have come a long way, with over 6 billion reported mobile devices around the world, with the growth showing no signs of slowing down.